Classification of multipartite entanglement in all dimensions

TL;DR

This paper develops a comprehensive classification framework for multipartite entanglement across all dimensions using SL-invariant polynomials, enabling systematic analysis of quantum states under SLOCC.

Contribution

It introduces a complete set of SL-invariant polynomials for classifying multiparticle entanglement in all dimensions, based on Schur-Weyl duality.

Findings

Constructed all SL-invariant polynomials for any number of qudits.

Derived a formula for the dimension of the SLIP space as a function of qudits.

Provided simplified expressions for qubit cases.

Abstract

We provide a systematic classification of multiparticle entanglement in terms of equivalence classes of states under stochastic local operations and classical communication (SLOCC). We show that such an SLOCC equivalency class of states is characterized by ratios of homogenous polynomials that are invariant under local action of the special linear group. We then construct the complete set of all such SL-invariant polynomials (SLIPs). Our construction is based on Schur-Weyl duality and applies to any number of qudits in all (finite) dimensions. In addition, we provide an elegant formula for the dimension of the homogenous SLIPs space of a fixed degree as a function of the number of qudits. The expressions for the SLIPs involve in general many terms, but for the case of qubits we also provide much simpler expressions.